Apparatus for annealing



April 1, 1930. H. M. ROBERTSON n 1,752,697

' APPARATUS FOR ANNEALING Filed Oct, 22, 1927 3 Sheets-Sheet lv 3 Sheets-Sheet 2 H. M. ROBERTSON APPARATUS FOR ANNEALING Filed 0G11. 22,- 1927 April 1, 1930.

April I 1930. H. M. ROBERTSON APPARATUS FOR ANNEALING Filed Oct. 224, 1927 mfr). m

Patented pr. \1, 1930` HARRY M. ROBERTSON, OF CLEVELAND, OHIO APBARATUS FOR ANNEALING Application led October 22, 1927. Serial No. 228,082.

This invention relates'to an apparatus for heat treating' or annealing bodies or castings,

' such as malleable iron castings and the like. One object of the inventioniis to provide an improved apparatus of this character wherein the periods required for both bring-v ing the temperature of the annealing chamlber up to the desired degree and for treating the castings are materially reduced, with the 10 result that the capacity of the apparatus7 is increased and cost of operationreduced.

Another objecty of the invention is to provide an apparatus of this character in which i A I rights 10. The base- 9 may compriseflongi` the heat is controlled in an improved manner to effect substantially uniform andrelativ e- A ings withinv other suitable material.

, ly quick treatment of all' the cast the annealing chamber.` a .A

Another object of the invention is topon-` struct an apparatus of this character in which the castings may be subjected to a non-oxidizing atmosphere, whereby the deterioration of the holding pots is reduced or substantially eliminated. A further object of the invention is to construct an apparatus of this character that is relatively simple and readily constructed and operated.

vOther objects of the invention will be apparent to those skilled in the art to which my invention relatesfrom the following description taken in connection with the accompanying drawings, wherein t Fig. lis a top plan view of apparatuses each embodying my invention. Fig 2 is a side elevation. Fig. 3 is a front elevation. Fig. 4 is a section (enlarged) on the line V4 4 of Fig. 2.

Fig. 5 is a section on the line 5--5 of Fig. 4. Fig. 6 is a section on the line 6 6 of Fig. 4. In the drawings, 1 indicates a suitable bed of concrete having insulating coverings 2, 3, of suitable fire-resisting materials, the latter forming the flooring for the oven or chamber 4. In the accompanying drawings I have shown two chambers 4 arranged side by side upon av single bed 1, such arrangement being vpreferable-since a single exhaust means o rw chimney (to be later referred to) may be uti-3f the adjacent main flue and leadingl Vwardly (preferably vertically) to or below lized for both chambers and thus reduce the costof installation.

Each chamber 4 is formed by an end wall 5 and side walls 6, 6, each formed of suitable fireaesisting material or materials, such as 55 firev brick 6 and an outer wall of brick 7 formed ofsuitable material such as diatomaceons earth. yThe inner side walls 6a of the two chambers are separated by a suitable insulation` 8 whichj permits of expansion of 60 ythese walls;V i' Extending from the end wall 5,

at in-elevation above the bed 1, is a base 9 supported at its outer end by suitable uptudinal and transverse channels or the like, on which Arests a fire bed 11 of lire brickorv The bed 11 co-operates with extended portions 6X of the side ywalls 6, 6a, to form a fire chamber 12. Each of the annealing chambers 4 and its fire cham- -70 ber 12 are covered by a top or roof of lirel brick 13 which is covered with a suitable insulation, such as diatomaceous earth powder. I

under pressure in anywell known manner.

That end of the chamber 4 opposite to the lire chamber 12 is open, as shown at 15, to permit the pots containing the castings to be annealed to be moved into the chamber 4 and removed therefrom'by suitable appa- 85 ratus, such as trucks. ,The opening 15 is closed by a door or wall 16 and the latter sealed when the apparatus is set in Operation.

17 indicates a main flue formed in the upper portion of each side wall 6, 6a, and eX- 90 tending longitudinally thereof, and substantially from end to end of said wall, the side wall being thickened and extended upwardly above the top 13 to provide for the iiue 17.

18 indicates flues formed in each of the side 95 walls 6, 6a, connected at their upper ends with downthe flooring 3 and each connected with one or more exhaust ports 19, 19, formed in and 10o leading through the side walls adjacent the Hooring 3. I preferably provide a pair of inlets or ports 19, 19a for each Hue 18. The

vertical Hues 18 adjacent to the opening'15 are s connected at their lower ends by a trans= verse Hue 2O formed in the Hooring 3v and4 By the provision of this Hue at that end of the `chamber 4 remote from the heating means it insures a sufficientsupply of the hot gases. t0

this portion of the chamber 4. The ,pairs of exhaust ports 19, 19, connected with the Hues 18 arel spaced from each other preferably uniformly from end to end` of the chamber 4.

As shown in Fig. 5, the upper ends of the vertical Hues 18 are slightly smallerin width than the width of the Hues 17. This permits the bottom of each Hue 17 at opposite sides of the adjacent Hue 18 to form a seat for a valve or damper 18', preferably comprising a relatively heavy plate which may be raised and lowered to close or open to any desired extent the adjacent Hue 18, and thus control the eX- haustof the products of combustion therethrough. The dampers -18 are operated in a mannerv to be later set 4forth. One end of each Hue 17 (preferably that end adjacent the fire chamber 12) is extended upwardly, as shown at 21 and the latter `is connected to a manifold 22 disposed transversely of and mounted on the top 13. The manifold may be suitably insulated on its inner surface to protect its metal shell. As shown, I provide one manifold 22 for the Hues 17-17, L17-17, formed in the side Walls, 6, for both chambers. The manifold 22 is connected by conduits 23, 23, with a main conduit 24', which in turn isconnected with the inlet of a Suitable suction or exhaust mechanism 25, pref-V erably comprising a casing and a fan mount# ed therein. The fan is connected to the shaft of a motor 26 and driven thereby to exhaust the products ofcombustion'and gases from 'the chambers 4. The suction mechanism 25 and motor 26 are mounted on a suitable support 27 carried' by an upright 28.

The outlet from the casing of the suction mechanism 25 is connected by a conduit 29 with a chimney or stack 30 through which the products of combustion drawn4 from' the chamber or chambers 4 are forced'and discharged into the atmosphere. i The top 13 is formed with one or more inlet openings 31, and these inlets have connected to them, supply Hues 32, connected and also providing a suitable wall or Hooring for the trucks or'other apparatus to run over.,

through a common supply Hue 33 to the stack or chimney 30.

34 indicates a valve or slide damper arranged to control theHow of the products of combustion and heat through the yconduit 24 underthe inHuence of the suction fan.

35 indicates a valve or damper mounted in the stack 30 above the connectionofthe supply Hue 33 therewith and 36 indicates a valve oi" damper mounted` in the Hue 33. The

dampers 35 and '36 are preferably independoxidizing condition therein.

The dampers 18 may be-operated by any desired means; but preferablyeach damper 18' has connected to it one end of a flexible.

member, such as a chain 37. The chain37 leads upwardly through an openinglin @the top wall ofthe adjacent conduit 17 aiid leads over asheave 38,then around a second sheave 39; fromthelatter sheave the chain ,leads downwardly and around a third sheavc 40 and then horizontally to, an"operating station at'some convenient point, for example,one end of the apparatus (preferably that 4end adjacent the Hre chamber)` ;4 all of the chains for controlling, the dampers for each chamber 4 leading to one4 operating-stm tion'. At the operating station means are provided for securing each chain end "in one of several predetermined positions, so that the damper connectedto it may be closed, or held in full open position or a partially open position. By preference the dampers are heavy and therefore self closing under the inHuenceof gravity, so that pull on any chain will lift the' damper connected to its innerend ofthe desired position. The free end' of the chain is connected-'to a barior rod 41 preferably terminatin in -a handle and "slides endwise through a'n opening 42formed in a `p'late 43 suitably'connected to the Walls 'of'theiapfparatus Theaod 4'1 is provided with a'seri'es of teeth or lugs one of which engages` the' face of the' plate 43' Vto hold the rod. 41 at any position to'which it is pulled or slid, -tofraise thel adjacent damper. By swinging' the rof'lf41in-its'guide opening 42. it maybe released'fror'n the plate and allowed to slide inwardly' due tothe weight of. the adjacent damper. when it is desired toclosc the latter. Each damper 18 4may be raised and lowered any desired distance and by their control or adjustment the inHuence of the exhaust mechanism 25 is effective to insure adequate circulation of the products of comi v leading from the annealing chamber 4, the

bustion throughout the annealing during each annealing operation.

In carrying outmy process, either or both chambers are first charged with pots filled with the castings to bev annealed, the cham.- ber closed and sealed, the damper 36 closed and the dampers 34 and 35 moved to full open position, and dampers 18 opened to the desiredxtent. Next the heating means are then ignited and the motor 26 started to drive the exhaust fan. Since the inlet of the casing surrounding the fan is connected through the conduits 24, 23, 23 and manifold 22 with the flues 21-17-18 and the latter have inlet openings or ports 19-19a,

products of combustion will be drawn or sucked through these ports andfdischarged from the fan casing through the stack to the outside atmosphere. In this step of my process the temperature of the chamber 4 is raised to approximately 1600 or 1650. degrees F. (depending on'the nature of the-,bodies being treated). Next, the supply of fuel isv reduced sufficiently and the damper 34 partially closed to reduce the suction effect and rate of exhaust of the products of com` bustion to produce and maintain a soaking temperature within and throughout all portions of the chamber lduring the period required to effect annealing. Next, the supply of fuel to the heating means is reduced orv cut-off so as to effect a relatively slow cooling; finally the damper 34 is fully open and supply of fuel cut oli (if not already cut off) to permit of rapid cooling of the chamber and bodies.

In accordance with my improved process, and the preferred form of construction for carrying out the process, the exhaust ports i are disposed at the lowest and most remote portions of the annealing chamber 4, `that is, adjacent its flooring and at substantially uniformly spaced points along its opposite sides and across the floor adjacent the receiving opening 15 at the farthest and lowest point from the heating means. In this form of construction, the products of combustionare caused to circulate to all portions as well as the lowest portion of the chamber and substanti ally uniformly over its entire area. with the result that heat is applied to and over and around all of the filled pots. In the use of my improved apparatus and the carrying out of the process therewith, I have been able i' to reduce the total period of time required for heating the chamber up to the desired degree of temperature (to-wit, substantially 1600 or 1650 degrees, F.) and the time required for treating or annealing the castings is reduced also materially as compared to apparatus of this character of which I have knowledge. By reducing the total period the apparatus is in use for each charging, a great saving of fuel results and the apparatus tion or exhaust mechanism, the chamber 4 may be enlarged to increase the capacity without increasing thel size ofthe lire chamber, which tends to reduce the cost of operation. I

When it is desired to produce a non-oxidizing atmosphere inthe chamber, I prevent air or oxygen or any substantial amount theyreof from coming into contact with the" pots during the period the chamber is being heated and during the period of annealing. To carry out these steps in this manner, I return the products of combustion, under pressure to' the chamber 4, preferably at a level above the outlet ports. This form of my method is effected by adjusting the vdampers 35, 36, as already set forth, so that the products will be forced through the supply flues 33, and 32 and inlets 31 to the chamber 4. In this latter method, deterioration of the pots is reduced or substantially eliminated and hence permits them to be maintained in use for an indefinite period.

To those skilled in the art to which my invention relates many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from its spirit and scope. My disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

That I claim is:

1. In apparatus of the class described, the combination of an annealing chamber having a flooring for charged pots, a lire box disposed at one end of and above said flooring for supplying heat to said chamberand a charging opening formed at the-opposite end of said chamber, exhaust conduits having their inlets in the lower portion and along the opposite sides of said annealing chamber from said lire box to said charging opening, and power driven means connected with said conduits for exhausting theproducts of combustion from said annealing chamber.

2. In apparatus of the class described, the combination of an annealing chamber having a flooring for charged pots, a lire box at one end of said chamber for supplying heat thereto and a charging opening formed at' the op- I lspaced along its opposite sides from said fire box to said charging opening, and means connected with said lines arranged to exhaust the products of combustion in said annealing chamber therethrough.

3. In apparatus of the class described, thel combination of an annealing chamber having a ire chamber for supplying heat thereto,- ues having inlets leading from said annealing chamber, said inlets being disposed adjacent the flooring of said annealing chamber and spaced along its .opposite sides a -flue chamber formed-in the flooring of said annealing chamber and disposed transversely thereof adjacent the charging opening therefor and connected to one of said fines, the top Wall of said flue chamber being in the plane of said flooring and formed with inlet openings substantially from end to end, and means connected with said lues arranged to exhaust the products of combustion in said annealing chamber therethrough.

4. ln apparatus of the class described, the combination of an annealing chamber having 'a fire chamber for supplying heat thereto,

flues having inlets leading from said annealing chamber, said inlets being disposed adjacent the flooring of said annealing chamber and uniformly spaced along its opposite sides, a I'iue chamber formed in the iiooring of said annealing chamber and disposed transversely thereof adjacent the charging opening therefor and connected at its opposite ends to the inlets adjacent said opening, the top wall of said iue chamber being inthe plane of said ooring and formed with inlet openings substantially from end to end, and means connected With saidv flues arranged to exhaust the products of combustion in said annealing chamber therethrough.

5. In apparatus of the class described, the combination of an annealing chamber having a flooring for supporting charged pots and a fire chamber for supplying heat thereto, flues having inlets along the side walls of said annealing .chamber adjacent its flooring and leading therefrom, means connected with said flues for setting up a suction effect therein to exhaust the products of combustion from said annealing chamber, and means for controlling the iow of the products of combustion through each of said flues. 4

G. In apparatus of the class described, the combination of an annealing chamber having a fire chamber for supplying heat thereto, a main exhaust flue formed in the upper portion of one side wall of said annealing chamber, separate fiues connectedat their upper ends to-said main flue and having inlets at their lower ends leading from said annealing chamber, and means connected with said main Hue for setting up al suction effect therein to exhaust the products of combustion from said annealing chamber.

7. In apparatus of the class described, the

vcombination of an annealing chamber having a fire chamber for supplying heat thereto, a main exhaust flue formed in the upper por- 4theirlower-ends leading from said annealing chamber, means connected with said main flue for settingup a suction eiect therein to exhaust the products of combustion from said annealing chamber, a damper for controlling each 'of said last mentioned iues, and means for operating each of said dampers.

8. In apparatus of the class described, the combination of an annealing chamber having heating means for supplying heat thereto, a plurality of exhaust lues having inlets leading from the lower portion of said chamber, means having its intake connected with said lues, whereby products of combustion are drawn from the lower portion of said chamber, and a conduit connected with the outlet of said means and leading to the upper portion oi said chamber, whereby the products oi combustion are supplied under pressure to the upper portion of said chamber.

9. In apparatus of the class described, the combination of an annealing .chamber having a flooring for supporting charged pots and a heating means for supplying heat thereto, a conduit system for the products of combustion having connections with said chamber at spaced points along its flooring and at its opposite sides thereof and through the top of said annealing chamber, and means in said system for drawing the products of combustion from the lower portion of the chamber and discharging them into its upper portion.

In testimony whereof, I have hereunto' subscribed my name. l

` HARRY M. ROBERTSON. 

